Fermented from specially selected rice, with half used as shiroki and half mixed with incenseash and used as kuroki (黒酒). Used in particular at the 大嘗祭(daijōsai) and 新嘗祭(nīnamesai) rituals held in late November, wherein the emperor would beseech the gods for a good harvest in the year to come.

This reading using the on'yomi is considered slightly more formal, rather like how words in English that have Latin or Greek roots are considered slightly more formal than synonyms that have Anglo-Saxon roots.